Fibre-reinforced concrete is concrete that uses other materials mixed in with the still liquid cement to reinforce the concrete structure. These fibres help make the concrete stronger and more resistant to temperature extremes. They also improve the concrete's water resistance. There are four types of fibre-reinforced concrete: steel fibre, glass fibre, synthetic fibre, and natural fibre reinforced concrete. Each type of concrete has different benefits and costs that influence how each is used on a construction site.
Steel Fiber-Reinforced Concrete
Steel fibre-reinforced concrete is basically a cheaper and easier to use form of rebar reinforced concrete. Rebar reinforced concrete uses steel bars that are laid within the liquid cement, which requires a great deal of prep work but make for a much stronger concrete. Steel fibre-reinforced concrete uses thin steel wires mixed in with the cement. This imparts the concrete with greater structural strength, reduces cracking and helps protect against extreme cold. Steel fibre is often used in conjunction with rebar or one of the other fibre types.
Glass Fiber Reinforced Concrete
Glass fibre-reinforced concrete uses fibreglass, much like you would find in fibreglass insulation, to reinforce the concrete. The glass fibre helps insulate the concrete in addition to making it stronger. Glass fibre also helps prevent the concrete from cracking over time due to mechanical or thermal stress. In addition, the glass fibre does not interfere with radio signals like the steel fibre reinforcement does.
Synthetic fibre-reinforced concrete uses plastic and nylon fibres to improve the concrete's strength. In addition, the synthetic fibres have a number of benefits over the other fibres. While they are not as strong as steel, they do help improve the cement pumpability by keeping it from sticking in the pipes. The synthetic fibres do not expand in heat or contract in the cold which helps prevent cracking. Finally synthetic fibres help keep the concrete from spalling during impacts or fires.
Natural Fiber Reinforced Concrete
Historically, fibre-reinforced concrete have used natural fibres, such as hay or hair. While these fibres help the concrete's strength they can also make it weaker if too much is used. In addition if the natural fibres are rotting when they are mixed in then the rot can continue while in the concrete. This eventually leads to the concrete crumbling from the inside, which is why natural fibres are no longer used in construction.